Mandating lower salt content in processed foods appears to hold the most promise for improving population health, models showed.

Action Points

Note that the bulk of dietary sodium intake is provided by salt in processed foods.

Point out that dietary advice is not an effective alternative when applied to populations at risk, and that mandatory salt restriction in processed food would have a significant beneficial effect.

Mandating lower salt content in processed foods appears to hold the most promise for improving population health, models showed.

Both voluntary and mandatory curbs on the amount of salt in processed foods would be cost-saving, although mandatory limits would potentially avert 20 times the disease burden a voluntary limit would, according to Linda Cobiac, of the University of Queensland's School of Population Health in Australia, and colleagues.

"Programs to encourage the food industry to reduce salt in processed foods are highly recommended for improving population health and reducing health sector spending in the long term, but regulatory action from government may be needed to achieve the potential of significant improvements in population health," the researchers wrote online in Heart.

"Food manufacturers have a responsibility to make money for their shareholders, but they also have a responsibility to society," they continued. "If corporate responsibility fails, maybe there is an ethical justification for government to step in and legislate."

Cobiac and her colleagues used modeling to evaluate the impact various interventions to reduce salt content in bread, margarine, and breakfast cereal would have on improving the public's health. They included:

Dietary advice delivered to those at high risk (systolic blood pressure greater than 140 mm Hg)

An incentive program that allows companies to purchase an endorsed logo from the Australian Heart Foundation for meeting a salt limit of less than 120 mg sodium per 100 grams (currently being used in Australia)

A program mandating reduction to that level

For the purposes of the analysis, the researchers used Australian dollars for the year 2003; one Australian dollar equals about 74 cents in U.S. currency.

Overall, Cobiac and her colleagues calculated, 610,000 disability-adjusted life years could be avoided over the course of the lifetime of the population if everyone reduced their salt intake to recommended limits.

Both interventions involving dietary advice would avert less than 0.5% of that burden, the voluntary curbs would avert less than 1%, and the mandatory limits would avert 18% -- 20 times more than the voluntary approach, according to the researchers' estimates.

Under all models, both the mandatory and voluntary reductions in salt content by food manufacturers are not just cost-effective, but cost-saving, taking into account costs and the reduction in cardiovascular disease risk.

On the other hand, according to Cobiac and her colleagues, offering dietary advice would not be cost-effective under any circumstances, even when aimed at those with the highest blood pressure risk.

Although the researchers were not able to account for potential changes in people's behavior in response to reduced product saltiness, they noted that "the evidence suggests that consumers are unlikely to compensate for the moderate reduction in dietary salt intake and, therefore, that targeting the food supply chain is an effective way to reduce population salt levels."

There is some support for that position, as the Institute of Medicine has recently called on the FDA to regulate the salt content of foods.

Commenting on the Australian study, Suzanne Steinbaum, DO, a cardiologist at Lenox Hill Hospital in New York City, said in a prepared statement, "Hypertension is clearly a public health problem, and education seems not to be the most effective means to fight it. Going to the food industry and changing the sodium content on a national level might in fact be the most effective way to deal with this public health epidemic."

The study was funded by the Australian National Health and Medical Research Council. Cobiac declared no conflicts of interest.